By David C.L. Bauer, Jacksonville Journal-Courier, Ill. The Tribune Content Agency

The first tick in the state to test positive for an emerging bacteria that can cause severe acute illness in people has been confirmed by state health officials.

A black-legged tick carrying ehrlichiosis, a disease caused by the bacteria Ehrlichia muris eauclairensis, was collected May 17 in Lake County as part of its surveillance program. The tick also is known as a deer tick.

Ehrlichiosis - which also can be transmitted through infected lone star ticks, which also are found in parts of Illinois - can easily be treated with antibiotics but can cause severe illness if left untreated, according to the Illinois Department of Public Health.

Black-legged ticks can be found in areas with woods, brush, leaf litter and tall grass. They are active from October to December and on any winter day above freezing, according to the state health department.

The tick species has been reported in Scott and Pike counties, and established - meaning at least six have been collected in a single year - in Morgan, Cass, Brown, Jersey, Macoupin and Sangamon counties, according to Illinois Department of Public Health surveillance.

Ehrlichia muris eauclairensis first was found in 2009 in a person in Eau Claire County, Wisconsin. All known human cases have been in Wisconsin and Minnesota.

"The discovery ... is a great reminder of the importance of our active tick surveillance program in Illinois," Illinois Department of Public Health Director Sameer Vohra said. "Anyone who spends time in wooded areas or brush, including hunters, should be sure to check for ticks every few hours and remove any that you find. If you experience common symptoms of tickborne illnesses - such as fever, sweats, chills, muscle aches, nausea or vomiting - see your healthcare provider immediately and let them know about tick exposure so that you can obtain testing and treatment that can prevent serious illness."